v4 property override error

[kriskowal]

In applications that mitigate prototype pollution by freezing Object.prototype and Function.prototype, Chalk v4 throws an error when attempting to assign template.constructor. Please consider back-porting a fix for the ^4 release range. Submitted here as a diff against the latest tag (Github does not let me base a PR on the tag).

https://github.com/chalk/chalk/compare/v4.1.2...kriskowal:chalk:kriskowal-mitigate-override?expand=1

We discovered this override through our transitive dependency through Babel.